Condensing Air Dryer

General Information

Removal of water vapor from gaseous samples prior to measurement is important to assure accuracy. The Columbus Instruments Condensing Air Dryer reduces the vapor content of gas samples to a 1°C dew point. The system has the added advantage of allowing the recovered water to be returned to the point of origin. This is especially important when it is desirable to maintain the moisture content of a sampled environment or when the water contains elements that are important to the process from which the sample has been drawn. Such cases exist in the measurement of soil, sewage and other aqueous solutions.

While chemical removal of water vapor is tolerable in some applications, its use can be costly and disposal difficult. The Columbus Instruments Condensing Air Dryer reduces the demand for chemicals by reducing water vapor pressure to levels that minimize chemical use. In a typical application, the Condensing Air Dryer precedes a chemical absorber in the air sample path. The liquid resulting from the Condensing Air Dryer may be returned to the process from which the sample was drawn. The 'pre-dried' sample may then be presented to a chemical agent for removal of any residual water required to achieve the desired vapor pressure.

The Condensing Air Dryer comprises a series of 10 vertical, parallel, stainless steel tubes (15" long, 0.5" outside diameter) encased within an aluminum housing that assures excellent thermal conductivity at the stainless steel / aluminum juncture. A series of thermo-electric coolers are affixed to the aluminum plates and powered at a rate determined by thermostatic control to maintain the stainless steel tubes at 1°C.

In practice, the gas sample is presented to the base of the selected tube with the resulting exhaust at the top. A second fitting at the base of the tube serves as an exit point for the condensate. All connections and wetted surfaces are stainless steel.

The Condensing Air Dryer is manufactured on a stand that facilitates placement over a water bath. The condensing assembly is mounted on an adjustable support that allows placement of the tube bases at a height of 20" to 25" (51cm to 64cm) above the bench-top, allowing clearance for the water bath beneath. Overall height is 38.5" (98 cm) when set to the highest position.